I've read 'The Alchemist', 'By the River Piedra I Sat Down and Wept.', and 'The Fifth Mountain'. I've also picked up 'Veronika Decides to Die' and 'Manual Of The Warrior of Light' but those have been staying on the 'to-read' list for a while. That's probably just me, though. I have to be in a certain frame of mind to be reading him.
Of the 3 I've completed, I liked 'Alchemist' and 'By The River...' more and have gone back to re-read them a few times. His writing is certainly inspirational, but after a while I sort of get the feeling that he's repeating himself. But when you're in the right mood for it, I'd say he's 'hot'.